Blow out coil



h. Z2, 1935. J. F. TRITLE BLOW-OUT COIL Filed March 10, 1933 Inventor: John F T'ritle, bg

Puentes Jm'zz, 193s UNITED STATES PATENT OFFICE BLOW OUT COIL mandenme-:Manna Eleohdecompany,acorpaationcfNewYork Anuman ma 1o. im. saw No. ma

4 om. (ci. zee-141) My invention relates to circuit-breaker blowout coils and to a method of manufacturing the same, and has for an object the provision oi' a circuit breaker blowout coil of low cost and 5 symmetrical shape, lending itself to the construction ot switches of improved space factor.

In the design of contactors of the air-break type, a blowout coil is connected in series circuit relation with the circuit breaker contacts so that the full load current of the circuit breaker is utilized to produce a strong magnetic ileld to blow out the arc resulting. from the opening of the circuit breaker. The continuous current rating of certain circuit breakers of this type, such as used in railway locomotives, is quite high, on the order of 2500 amperes, so that a sub.- stantial amount of copper must be used in the blowout coil to prevent overheating. Similarly,

a relatively large Contact area must be providedA 20 for the inner end or a splrally wound blowout coll to prevent overheating,

Gn a looomo'tire the permissible space for the control equipment is limited and it is therefore important to design the blowout coil oi' the con* taeter or circuit breaker so that the blowout is not the limiting feature .ln width of lo oontaotor when a spirali? wound blown used, to construct the coll so that ily the same conducting are?. lo 'pro- 'tbe inner .enc oi the coil as is in each of its turns.

Er. lng out the present invention in one thereof, I provide a spirally Wound blowout coll mmh lo not the limiting feature in the ltn ne circuit breaker. More speelflollf, provino a 'if-shaped end :m the conductor forming blowout coil and spirally wind the conductor between the .f-sl1aped end to producir a blowout coil of symmetrical shape which con f ples a minimum amount of space and yet pr vides me maximum ourrent-osrrying capa The two ends oi the Y-s`naped end are con" nected to carry jointly the load current flowing through `the main body of the conductor, these ends also forming supports for arc blowout plates.

For a more complete understanding of my invention reference should now be had to the drawing, Fig. 1 of which shows an elevation of the arc chute and main current-carrying parts of a circuit breaker to which my invention has been applied; Fig. 2 shows a perspective view o! the blowout coil construction in accordance with my invention; Fig. 3 shows the Y-shaped end oftheblowoutcoilofrig.2;while1"igs.4and

showmodincatiomoi'tbeY-shapedendof the blowout coll.

Referring now to the drawim, I have shown my invention in one form as applied to a circuit breaker 10 having a fixed contact 11 and a movable contact 12. The operating means for l'the movable contact 12, the supports, etc. are

notshcwnastheyformnopartoimypresent invention. A blowout coil 13 of high conductivity material such as copper is connected in series circuit relation with the contacts 11 and 12 of the circuit. breaker so that the load current ilowing through the blowout coil 13 produces a strong magnetic flux in the magnetisable pole pieces or blowout plates 15 extending in spaced relation on opposite sides of the contacts 11 and 12 and connected by a magnetizablc member 16 extending through the center o! the blowout coil.

The blowout coil 13 is formed from a single strip 18 of conducting material. The nrst step in constructing the blowout coil is to divide or split the end oi the strip conductor 18 and to spread apart the divided ends 19 and 20 a dlr:u tance greater than the width of the strip. The conductor 1S is splrally wound upon itself so that the spaced end. portions lil and 20 form leads to the inner 3l. of. the coil. It be observed the ends lil and 20 provide substantially conducting are. the conductor 18. By bringing out 'the leads from. *le inner' om the coll on oppasite sides nl coil o. well om design'. is obtained. The "A o t e. limiting feature in the r il@ of Fig". l,

tup supp-. .ing omni-J by olderng or lxim; the blowout coil in position' are the screws 23 and 2d extending through the holes provided in nthe end i9 of the blowout coil and into the supporting member 22. Similarly, the end 20 of the blowout coil is scoured by screws (not shown). The ends 19 and 20 are also used to support the magnetizable pole pieces or blowout Vplates 15 and the core 16. One of the magnetizahe pole pieces is held in position by means of the bolts and 31 which pass through it and are screw-threaded into the end 19 of the coil. Similar bolts (not shown) cooperate with the end 20 of the coll to support the other pole piece. The screwvthreadedendsoftheboltsarearrangedtobe screwedintotheendslandloftbeblowxt lli a compact construction of the blowout coil, the coil readily-lends itself to the performance of other functions as, for example, the compact and stable method of supporting the pole pieces.

It will, of course, be understood that instead of dividing the end of the conductor 18 a Y- shaped end may be formed on the end of the conductor by welding or brazing a U-shaped conductor 33 having the `same cross sectional area as the conductor 18 to the end of the conductor 18 as shown in Fig. 4. Or, an alternative is shown in Fig. 5 wherein separate conductors 36 and 37 having the same cross sectional area as the conductor 18 are welded or-brazed to the conductor 18 to form a Y-shaped end.

While I have shown a particular embodiment of my invention, it will be understood, ofcourse, thatI do not. wish to be limited thereto since ymany 'modications may be made, and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the v true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. 'Ihecombination with a circuit breaker of a blowout coil therefor, comprising a spirally wound strip conductor one end of which is divided longitudinally to provideleads on opposite sides of the turns of said coil to the inner end of said coil, astationary contact for said circuit breaker, means supporting said leads of said conductor and said stationary contact, a pair of blowout plates for said circuit breaker, means for supporting said blowout plates from said divided leads of said conductor and on opposite sides of said stationary contact, and a magnetizable member extending through said coil and secured to said plates. f

2. A blowout coil for circuit breakers comprising a strip conductor. divided longitudinally to provide spacedv end portions therefor, saidconductor being spirally wound between said end portions to form a plurality of turns, said end' l 1,988,927 coil. Thus it will-be seen that besides providing from said turns, blowout plates on opposite sides of said coil secured to said end portions, and a magnetizable core extending through the center of said coil and between said plates.

3. A blowout coil for circuit breakers comprising a strip conductor, one end being divided longitudinally to provide spaced end portions there-4 for, said conductor being spirally wound between said spaced end portions to form a coil having a plurality of turns, said end portions extending tangentially from the inner turn of said coil and being spaced laterally from said turns of said coil, the outer turn of said coil extending between said end portions and terminating in the opposite end of said conductor, said opposite end extending substantially at right angles to a plane taken through said end portions, blowout plates on opposite sides of said coil secured to said end portions, a magnetizable core extending through the center of said coil and between said plates, a stationary contact, a conductor, fastening means electrically connecting said conductorr to said stationary contact and to said end portions, saidconductor forming a support for said stationaryV contact.

fl. 'A blowout coil for circuit breakers comprising a strip conductorformed of material having a conductivity substantially equal to that. of copper, one end of said conductor being split longitudinallyto provide spaced end fportions therefor, said conductor' being spirally .Wound between' said end portions to form a plurality of turns, said end portions being spaced laterally from said turns of said coil and extending tangentially from the inner turn vof said coil, a

magnetizable core extending through the centerV plates, a supporting conductor having one end v.- secured to' said end portions and its opposite f end secured to said stationary. contact, the outer turn of said coil extending between said end portions and terminating .inv spaced relation with.

said end portions. l a.

' JOHN F. 

